The 94-year-old monarch, who has been patron of the Royal Voluntary Service (RVS) for almost 70 years, took part in a video call with the Duchess of Cornwall to thank volunteers from the organisation.
The charity is marking the first anniversary of the NHS Volunteer Responders scheme and more than a million new helpers have signed up since last March.
The Queen told them: “Thank-you very much indeed, very interesting to hear what you (have) been doing, I think it’s wonderful work and I do thank everybody for, and all the others too, who have been volunteering it’s been a great, great help over this very difficult year.”
Camilla, who is the RVS president, also praised the efforts of the volunteers, saying: “Thank-you all very much for all you’ve done throughout the year, throughout the pandemic. We couldn’t have done it without you.”
More than 1.6 million tasks have been carried out by NHS Volunteer Responders under the scheme delivered by the RVS and the GoodSAM app, the Queen and duchess were told.
Support has included shopping and prescription collection, transport to and from medical appointments, stewarding at vaccination sites and providing “check in and chat calls” for those who are self-isolating, vulnerable or elderly.
A number of royal women have befriended elderly people as part of the scheme, with the Duchess of Cambridge regularly chatting to Len Gardner, 85, from Batley, West Yorkshire, while the Countess of Wessex speaks to Edna Farley, 89.
The RVS video call came after Doris Winfield, 86, from Rickmansworth in Hertfordshire and who was befriended by Camilla through the check in and chat scheme, died in January.
Ahead of the call this week, the duchess recalled how she had enjoyed “lots of happy conversations” with Ms Winfield.
During the video call, RVS chief executive Catherine Johnstone told the Queen and duchess: “I couldn’t be prouder of the way in which Britain has stepped forward to volunteer.”
Retired police officer Tracy Clarke, from Gateshead, told the royals how she worked at the RVS Gateshead Home Library Service delivering books to isolated people.
The Queen replied: “Rather different work from the police I should think.”
She went on to say: “Yes and books are very important to people.”
RVS volunteer Sue Cadwallader from Northumberland said helping out had brought her close to her son Sam and gave her “direction” and “purpose” after retiring.
She added: “I thought actually working with my son, actually (getting) to see him once in a while as well, which is quite nice.”
The Queen nodded and gave a huge smile after hearing Ms Cadwallader talk about being closer to her son.
Anderson Akponeware, an NHS Volunteer Responder based in Middlesbrough, dedicated his spare time to supporting his community whilst juggling studying for his PhD and home-schooling.
He said: “When the call was made by the NHS and the RVS to support the vulnerable and those who were shielding, I didn’t think twice before signing up – so for close to a year now I’ve been a check in and chat volunteer.
“People have been living in their own small bubbles, and I wouldn’t have known how isolated those small bubbles could be until I took on this role.”